Energy transfer between two coupled inductors may occur through the use of a transmitter generating an oscillating magnetic field and a receiver converting the oscillating magnetic field into electric power. In many energy transfer systems the conversion is from oscillating magnetic field into a direct current (DC) voltage.
The DC voltage is at least in part a function of magnetic field intensity and the coupling between the inductors. If the magnetic field intensity decreases or the coupling between the inductors decreases, then DC voltage may also decrease. If the DC voltage drops below the minimum voltage required by the load then energy transfer ceases.